The 104.9 frequency originally went on the air February 15, 1964 from the basement of station owner Joseph Lepp as WCBW in Columbia, IL, and was a typical small town radio station. In 1980, the station was sold to Continental Broadcasting, and the station became the first station in the St. Louis area with a format of Contemporary Christian Music, still with a weak 3,000 Watt signal based in Columbia, IL, but it could be heard in much of the St. Louis area. The station was called "104.9 The Bridge" at the time.
In 1993, the station was granted a major power upgrade allowing it to move to the St. Louis Master antenna site in Shrewsbury, MO, and upgrade from 3,000 watts to 25,000 watts, making the 104.9 frequency a full market St. Louis signal. That made the station much more valuable, as did deregulation allowing operators to own several different FM stations in a market in 1996.
In 1997, the station was sold to Jacor Broadcasting, who also owned urban powerhouse KMJM, which was then at 107.7 FM. Instead of installing a new format on the 104.9 frequency, KMJM was relocated to the weaker 104.9 MHz frequency to allow its new CHR station KSLZ a better signal into the suburbs on the full 100,000 watt class C 107.7 frequency as it remains to this day.
By 1999, KMJM became owned by Clear Channel Communications, who also owned KATZ AM & FM. KATZ-FM was an Urban Adult Contemporary format playing mostly slower R&B, while Majic played a format consisting mostly of Hip Hop/Rap and current R&B Hits. The formats on the two stations would swap, and Majic would take the Urban Adult Contemporary format from 100.3, while maintaining most of the same staff, and 100.3 was rechristened as "The Beat" with a mainstream urban format that would last until October 2009.
On November 7, 2012, at 9 AM, KMJM and its urban AC format moved to 100.3 FM (ironically, KATZ-FM's former frequency), replacing classic rock-formatted KBWX ("The Brew"). The 104.9 frequency changed its format to rhythmic CHR, branded as "Wild 104.9." KMJM and KBWX also swapped call letters, which were approved a few days later.